sulphonamide-resistant Gram-negative bacilli

allergens in maltworkers with extrinsic allergic alveolitis than in the rest of the maltworker population, and (c) atopic maltworkers had a significantly lower rate of skin sensitivity to occupational allergens than non-atopic workers. The first observation is not surprising, since extrinsic allergic alveolitis is not due to a type 1 allergic reaction. The second is of interest, since it suggests that the type 3 allergic reaction responsible for the disease may be accompanied by a type 1 reaction to the same allergen. The third is difficult to explain except, perhaps, on the rather dubious hypothesis that skin sensitivity to common allergens in some way inhabits the development of skin sensitivity to occupational allergens. It would appear, however, that this phenomenon does not protect such patients from the type 3 antigen-antibody reaction believed to be responsible for extrinsic allergic alveolitis. With increasing mechanisation of the malting process the prevalence of this disease is likely to diminish rapidly, and there may never be another opportunity to confirm or refute the hypothesis that in most cases extrinsic allergic alveolitis is a pulmonary allergic reaction to inhaled spores of A clavatus. We thank Dr Robert Whitelaw and Dr J Douglas Bell of the Employment Medical Advisory Service for their help in the field survey; Drs B R Hillis, R N Johnston, A P Littlewood, R S McNeil, W D Murray, and B H R Stack for making many of the clinical assessments; and Miss Jane Williamson for typing the manuscript. We also wish to acknowledge the valuable help we received from the Scottish malting industry and the willing and cheerful co-operation we obtained from the maltworkers. This study was supported by a grant from the Secretary of State's medical research fund.